Bone marrow is the major site of blood cell formation and, while at birth it is found within nearly all bones, by adolescence it is located primarily within axial bones (e.g., pelvis and femur). The bone marrow exists in the inner portion of bones, referred to herein as the marrow space, and contains the precursor stem cells that ultimately become red blood cells, white blood cells, and platelets.
Bone marrow aspirations and biopsies are common tests used to evaluate the bone marrow for leukemias and other hematologic disorders, for example. A sampling of the marrow from the marrow space can determine cell number, cell shape, and cell maturation. Special pathologic stains and molecular studies on the marrow specimens can establish certain diagnoses. Sampling of marrow from the marrow space may occur at multiple times during a patient's treatment program to assess progress.
Current techniques for sampling bone marrow generally require needle penetration of bone each time a sample is taken, which can be painful for the patient. In patients who require multiple samplings during their care, this can be a repeated painful episode. It may require additional trips to the hospital and repeated anesthesia events.
An apparatus that is often used for sampling bone marrow is shown in FIGS. 13 and 14. The apparatus 150 includes a bone penetration needle 152 that has an operative portion 154 extending through a cannula 156 as shown in FIG. 13 to contact and penetrate the bone (not shown in FIG. 13). After such penetration, the bone penetration needle 152 is removed from engagement with the cannula 156 which remains in place, as shown in FIG. 14. An aspiration or biopsy needle 158 is passed through the cannula 156 into a marrow space of a bone 160 to retrieve marrow, and then withdrawn from the cannula 156. Other sampling devices or exchange apparatus such as a wire are also commonly used through the cannula.
Another technique for sampling bone marrow is described in U.S. Pat. No. 8,690,791 and utilizes bone harvesting apparatus that includes a driver operable to be releasably engaged with an intraosseous device. The intraosseous device includes a cannula having a first end that penetrates bone and bone marrow and to allow retrieval of portions of bone and/or bone marrow. The cannula has a second end releasably engaged with bone marrow sampling equipment. A removable trocar has an inner channel that conveys portions of bone and/or bone marrow and a side port communicating with the inner channel.
Another procedure that requires needle penetration of bone is intraosseous infusion. In intraosseous infusion, a resuscitative fluid or drug solution is injected directly into the bone marrow of the patient's bone through an intramedullary infusion device, from where it is transported throughout the patient's body.
One intramedullary access device for use in intraosseous infusions is described in U.S. Pat. No. 7,833,204 and includes a tubular conduit having a closed distal end and a proximal end with a length sufficient to pass through the cortical region and extend into the cancellous region of a bone. A flange circles the outside of the proximal end of the conduit. A penetrable diaphragm is positioned within the tubular conduit that extends into the bone. Outlet structures are positioned along the outer side surfaces of the tubular conduit, each creating an outlet opening so as to allow fluid flow between the tubular conduit and the cancellous region of the bone. A compressible member is positioned over the outlet openings at the distal end of the tubular conduit.